The present invention relates to an image processing apparatus and method and, more specifically, to an image processing apparatus having a function to extract characteristics of an input image and to a method to extract the same.
A color printing system, such as a color printing apparatus which digitally processes color image data and outputs the data to a color printer to obtain a color image and a digital color copy machine which electrically reads a color original by decomposing colors of the original and copies a color image by printing an image based on the obtained color image data on a printing sheet, has become popular.
As these systems have become commonly used, the demand for higher quality of printing a color image has increased. Especially, it is demanded to print black characters and lines in darker black color and more sharply. When an original written in black is color-decomposed, signals of yellow, magenta, cyan, and black are generated to represent the original black color. By performing printing operation in accordance with these generated signals, the original black is reproduced by the four colors, thus without placing ink of the four colors exactly in the same positions, the reproduced image has blurred outlines in black thin lines, which prevents the reproduced black line from looking black, or makes black characters or lines look blurred. Thus, the quality of a printed image may drop considerably.
In order to overcome the above-mentioned problem, there is suggested a method to extract color information on black portions or on color portions other than black in image signals, and extract characteristics of space frequencies of thin lines, screened dot, or the like, thereby to detect an area of black characters or colored characters, for instance, further to divide the image signals into areas of halftone images and screened dot images and to apply a process which is proper to each area, and to simplify black color reproduction if the area is a black character portion.
However, according to the aforesaid conventional method, in order to reproduce characters whose font is Mincho (one of Japanese character types), for instance, which changes in thickness of a character in different parts of the character, there is a problem in that borders of the character are so clearly jagged that the border can be apparently recognized. Further, in a case where a character exists in a screened dot image, since the edge of the character can not be distinguished from the edge of a dot, a process for black characters can not be performed. Therefore, black characters are not always processed with proper operation, which prevents the reproduction quality of an image from improving.
Further, since a character area can not be recognized in high resolution, a rate of character recognition (known as optical character reader) remains low.
The present invention has been made in consideration of the above situation, and has its object to solve aforesaid conventional problems.
Accordingly, an object of the present invention is to improve recognition quality of characteristics of an input image. Especially, to improve recognition of character area of the input image.
According to the present invention, foregoing object is attained by providing an image processing apparatus comprising: input means for inputting image data representing an image; detecting means for detecting a character portion of the image; judging means for judging a width of the character portion; and processing means for processing the image data in accordance with the judgment result of the judging means.
Further, another object of the present invention is to apply a proper process on black characters.
Still another object of the present invention is to provide a copying apparatus capable of reproducing an image more faithful to an original image.